Sonic fans never gave a shit where Bob Blackburn grew up. To the contrary, he was considered a Northwesterner because of his Oregon background, and no one thought about California. Wikipedia:
Blackburn grew up in the Los Angeles area. As a child, he was bedridden with tuberculosis.[1] While listening to college sports broadcasts, he dreamed of being behind the microphone. Blackburn's uncle had told him his strength was in his "loud voice," so a career in broadcasting seemed like a good idea.[2]
Blackburn managed to land a job at a radio station in Santa Ana, California in 1942, and worked his way up. He also attended college at Fresno State Normal School. Eventually, he landed a job with the Portland Beavers Pacific Coast League baseball team, and was part of the Beavers' broadcast duo with Rollie Truitt on station KWJJ for 18 years. During that time, Blackburn was also a play-by-play announcer for University of Oregon and Oregon State University (OSU) football games in Portland, over the Tidewater Oil Company's sports radio network. In 1953, he became the sports director of KEX, a station where he also had his own afternoon disc jockey show. In 1957 he moved to KPOJ also doing the afternoon shift. In 1958 he moved to KXL, and then back to KPOJ in 1959.
When OSU created its own sports radio network in the late 1950s, Blackburn became the radio voice of Oregon State football and basketball. He was employed by the network flagship station, KEX of Portland. In 2002, Blackburn was inducted into the Oregon Sports Hall of Fame for his Special Contribution to Sports in Oregon.
When the SuperSonics joined the NBA in 1967–68, the team needed a play-by-play voice...